The blind recognition of channel coding is playing more and more important roles in smart communications. The paper took rate below 1/2 binary cyclic codes to research, we established a model using counter of continuous bits 0. At the basic of studying the features of binary cyclic codes, when the condition about the rate is satisfied, we made a statistics of the continuous bits 0 in a long sequence of code words to get the length of code word n and the length of information k. In the condition of higher BER simulations, we improved the method to make it suitable for estimating the parameter.